2025 COA Annual Meeting: Greater Kinematic Alignment Following Unicompartmental Compared to Total Knee Arthroplasty: A Randomized Clinical Trial

Thirty patients with knee osteoarthritis were randomized to receive either unicompartmental knee arthroplasty (UKA; n=12) or total knee arthroplasty (TKA; n=18). The primary outcome of interest was gait biomechanics, including sagittal and coronal knee angle metrics during walking. Secondary outcomes of interest included the Oxford Knee Score (OKS) and the WOMAC sub-scores for pain, stiffness, and physical function. Outcomes were assessed pre-operatively and at one year post-operatively. Overall, the results of the study revealed that UKA was associated with gait patterns more closely resembling native knee biomechanics, including greater sagittal knee angle correlation and lower coronal knee angle RMSE (F4,25, P=0.010), while PROMs improved similarly in both groups (p<0.001). These findings suggest UKA better preserves physiological knee kinematics compared to TKA, which may explain prior observations of enhanced recovery and function with UKA.